Process for preparation of particles

ABSTRACT

The present invention is directed to a process for the preparation of polysaccharide-grafted polymer particles wherein the polysaccharide is preferably a β-1,4 linked polysaccharide, comprising miniemulsion polymerisation.

TECHNICAL FIELD

The present invention relates to a process for the preparation ofpolysaccharide-grafted polymer particles using miniemulsionpolymerisation, and to the particles themselves and their uses, such asdelivery to fabric during laundering.

BACKGROUND OF THE INVENTION

The deposition of a benefit agent onto a substrate, such as a fabric, isa well known method of imparting desirable properties to the substrate.In laundry applications the range of “benefit agents” is diverse andincludes fabric softeners and conditioners, soil release polymers, shaperetention agents, anti-crease agents, ease of ironing aids, perfumes,lubricants, texturising agents, insecticide repellents, fungicides,photofading inhibitors, fluorescers, sunscreens and many others.Deposition of a benefit agent is used, for example, in fabric treatmentprocesses such as fabric conditioning to confer, for example, softeningbenefit to the fabric.

Conventionally, the deposition of the benefit agent has had to rely uponattractive forces between the oppositely charged substrate and thebenefit agent. For example, cotton is negatively charged and thusrequires a positively charged benefit agent in order for the benefitagent to be substantive to the cotton, i.e. to have an affinity for thecotton so as to absorb onto it.

However, adverse charge considerations can place severe limitations uponthe inclusion of benefit agents in compositions where an activecomponent thereof is of an opposite charge to that of the benefit agent.For example, cationic fabric conditioning agents are incompatible withanionic surfactants in laundry washing compositions, hence fabricconditioning products are usually separate from main wash products.Furthermore, the substantivity of the benefit agent can be severelyreduced and/or the deposition rate of the benefit agent can be reducedbecause of the presence of incompatible charged species in thecompositions. The conventional way around this problem is to add benefitagents during the rinsing step of a treatment process so as to avoidadverse effects from other charged chemical species present in the mainwash compositions. This has clear cost disadvantages to the consumer andinstigates the need for two separate products instead of one.

However, in recent times, it has been proposed to deliver a benefitagent in a form whereby it is substituted onto another chemical moiety,which itself has an affinity for the substrate in question.

PRIOR ART

WO 99/36469 is directed to a polysaccharide conjugate capable of bindingcellulose. Locust bean gum (LBG) is grafted to proteins, such as enzymesor anti-bodies or perfume loaded particles. This is delivered to thefabric during the laundering. The LBG attachment is achieved byenzymatic oxidation of the LBG using galactose oxidase to introducealdehyde groups. These aldehyde groups are then reacted with glucoseoxidase (using sodium cyanoborohydride) to form an LBG with chemicallybound glucose oxidase. This procedure for preparing the material iscumbersome and involves numerous steps using ‘conventional’ organic(enzymatic) chemistry, such as purification of LBG, introducing aldehydefunctionality to the LBG and coupling of this to an enzyme (via theenzymes hydroxyl functionality).

WO 99/36470 is also directed to polysaccharide conjugates that are ableto bind cellulose, where the polysaccharide is attached to a particlecontaining perfume. The particle may be a range of materials, includingsilica. Perfume is allowed to infuse into macroporous silica particlessimply by absorption, adsorption, impregnation and/or encapsulation. Thepolysaccharide, e.g. LBG, is then merely added to the perfumed particlesand is physically adsorbed onto the particle surface. The LBG aidsdeposition in a wash environment.

European patent application number 01306632.9 is directed to a waterdispersible particle comprising a deposition enhancing part of one ormore polymeric units and a benefit agent attached to the depositionenhancing part. Preferably the deposition aid has a hydrolysable group(based on esters), such as Cellulose Mono-Acetate (CMA). The modifiedparticles are prepared by reaction of acid functional beads by acumbersome multi-step ‘conventional’ organic chemistry technique. Thisrequires several time consuming (and commercially nonviable for highvolume production) centrifugation stages and the preparation of an aminefunctional CMA by reaction of CMA with ethylene diamine using carbonyldiimidazole as coupling agent. The amine functional CMA is then reactedwith acid functional beads (obtained externally) using ethyl dimethylaminopropyl carbodimide as coupler. This results in CMA graftedparticles which exhibit enhanced wash deposition.

Our GB patent application number 0229806.5 is directed towards a processfor the preparation of polysaccharide grafted latex particles whichcomprises conventional emulsion polymerisation and to the materials thusproduced. The particles have been used as carriers for benefit agents,including softeners, for deposition under main wash conditions. However,constraints on the amount of benefit agents which can be incorporatedinto the particles and the types of monomer units that can be used,which are inherent to conventional emulsion polymerisation, areinevitable.

Despite these advances, the need remains for more efficient depositionsystems which are more cost effective and which are capable ofdelivering a wider range of benefit agents under a range of useconditions (e.g. main wash conditions).

We have now surprisingly found that a process for the preparation ofpolysaccharide-grafted polymer particles that uses miniemulsionpolymerisation, rather than conventional emulsion polymerisation, allowsthe incorporation of a far wider range of (for example more hydrophilicbenefit agents) and increased levels of benefit agents into the particleitself, and also allows the use of a wider range of monomer types, whichin turn results in greater benefit delivery to the substrate.

DEFINITION OF THE INVENTION

A first aspect of the invention is a process for the preparation ofpolysaccharide-grafted polymer particles, wherein the polysaccharide hasβ-1,4 linkages, wherein the process for preparation comprisesminiemulsion polymerisation of monomers.

According to a second aspect of the invention, there is provided amethod of treating fabric, preferably cotton, comprising contacting thefabric with the polysaccharide-grafted polymer particles obtainable bythe process of the first aspect of the invention.

According to a third aspect of the invention, there is provided the useof a polysaccharide-grafted particle obtainable by the process asdefined above in the treatment of fabric, preferably cotton, to deliverone or more benefit agents to the fabric.

According to a fourth aspect of the invention there is provided alaundry treatment composition comprising the polysaccharide-graftedpolymer particle as produced by the process of the first aspect of theinvention.

The invention further provides the uses of the laundry treatmentcomposition of the fourth aspect in the treatment of fabric and in thedelivery of benefit agent thereto, and a corresponding method oftreating fabric.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed towards a miniemulsion polymerisationprocess for preparing polysaccharide-grafted polymer particles, such aslatex particles. The particles may contain additional benefit agentsand/or act as the benefit agent itself. We have found that suchpolysaccharide-grafted polymer particles have been deposited during themain wash onto fabric, preferably cotton, at levels of from 8 to 28times greater than non-polysaccharide control particles.

The term “latex” or “latex particle” as used herein is defined as astable colloidal dispersion of a polymeric substance in an aqueousmedium. The polymer particles are usually approximately spherical and oftypical colloidal dimensions. Particle diameters may range from about 30to 500 nm (The Encyclopedia of Polymer Science and Engineering, SecondEdition, Volume 8, Page 647, John Wiley and Sons Inc. (1987)).

Emulsion polymerisation techniques are described in “EmulsionPolymerisation and Emulsion Polymers”, P. A. Lovell and M. S. El-Aasser(eds.), John Wiley and Son Ltd (1997).

Core/shell emulsion polymerisation techniques are described in L. W.Morgan, J. Appl. Polym. Sci., 27, 2033 (1982), V. L. Dimonie, A. Klein,M. S. El-Aasser and J. W. Vanderhoff, J. Polym. Sci., Polym. Chem., 22,2197 (1984), D. I. Lee, in “Emulsion Polymers and EmulsionPolymerisation” D. R. Bassett and A. E. Hamielec (eds.), ACS SymposiumSer., No. 165, p. 405 (1981) and W. D. Hergeth, K. Schmutzler and S.Wartewig, Makromol. Chem., Macromol. Symp., 31, 123 (1990).

THE PROCESS FOR PREPARATION

Miniemulsion polymerisation is well known in the art and the term“miniemulsion polymerisation” as used herein means the same as the termknown in the art. Numerous scientific reviews of miniemulsion techniqueshave been published:

-   1) El Aasser, M. S., Miller, C. M., “Preparation of latexes using    miniemulsions”, In: Asua, J. M., editor. Polymeric dispersions.    Principles and applications. Dordrecht: Kluwer, p. 109–126 (1997)-   2) Sudol, E. D., El Aasser, M. S., “Miniemulsion polymerisation”,    In: Lovell, P. A., El Aasser, M. S., editors. Emulsion    polymerisation and emulsion polymers. Chichester: Wiley, p. 699–722    (1997)-   3) Asua, J. M., Prog. Polym. Sci., 27, 1283–1346 (2002)

Miniemulsions generally lie in between macroemulsion and microemulsionsin terms of droplet size and emulsion stability. Miniemulsion dropletstypically range in size from 50 to 500 nm. The emulsion can be stablefor as little as a few days or for as long as a month. The droplets maybe stabilised by the addition of an ionic surfactant (e.g. sodium laurylsulphate) and a cosurfactant. The latter usually consists of either along chain alkane (e.g. hexadecane) or an alcohol (e.g. hexadecanol).The function of the cosurfactant is twofold; it acts in combination withthe surfactant to create a barrier to droplet/droplet coalescence byarranging at the oil-water interface and it also limits diffusion of theoil phase from smaller to larger droplets by virtue of its low watersolubility.

Miniemulsions are typically formed by subjecting an oil (monomer),water, surfactant and cosurfactant system to high shear fields createdby devices such as ultrasonifiers, homogenisers and microfluidisers.These devices rely on mechanical shear and/or cavitation to break theoil phase into submicron size droplets. When monomer is used as the oilphase, free radical polymerisation can subsequently be carried out bythe addition of an initiator (e.g. ammonium persulphate). Such a processin which the miniemulsion droplets are converted to polymer particles isreferred to as miniemulsion polymerisation. For the sake of clarity, by“miniemulsion droplet or emulsion droplet” as used herein is meant theminiemulsion droplet before it is polymerised, and “emulsion particles”means the polymerised miniemulsion droplets.

In conventional emulsion polymerisation the monomer diffuses through theaqueous phase to the surfactant formed micelles. Particle nucleationbegins and proceeds in these micelles and the monomer droplets merelyact as a reservoir of monomer. Whereas in miniemulsion polymerisationthe presence of cosurfactant and the use of high shear results in theformation of small monomer droplets. These droplets are polymeriseddirectly and no monomer diffusion to micelles occurs and no particleformation occurs within micelles. Such differences are well documentedin the literature for example in “Emulsion Polymerisation and EmulsionPolymers”, Edited by P. A. Lovell and M. S. El-Aasser, John Wiley andSons, Chapter 20, page 700–703.

In conventional emulsion polymerisation, the benefit agent can only beincorporated at relatively low levels (typically 10% or less by weightof the particle) and must be sparingly water soluble, have low molecularweight (typically under 1,000 g) and have similar water solubility anddiffusion rate as the monomer. However, for the miniemulsionpolymerisation, none of these restraints apply. This allows theincorporation of higher levels (typically from 10 to 60%) and a widervariety of benefit agents, such as completely water insoluble andpolymeric benefit agents (e.g. silicone resins and thermoplasticelastomers), in polymer particles, which cannot be achieved usingconventional emulsion polymerisation techniques.

The process of the invention is for the preparation ofpolysaccharide-grafted polymer particles by miniemulsion polymerisation.

Preferably, the process comprises the steps of:

-   (a) preparation of a miniemulsion, and-   (b) polymerisation of the miniemulsion of step (a),    -   wherein grafting of the polysaccharide to the polymer particles        occurs in step (b).

Step (a) may consist of the following sub-steps:

-   (i) monomers are mixed with a cosurfactant to form a mixture (y),-   (ii) a polysaccharide and a surfactant are dissolved in water to    form a mixture (z),-   (iii) (y) and (z) are combined and subjected to high shear to form    an emulsion,-   (iv) the emulsion of step (iii) is then subjected to further shear    (such as sonication or other suitable high pressure homogeniser such    as a Microfluidiser or a Manton Gaulin homogeniser) to form a    miniemulsion.

Preferably, an initiator is added to the miniemulsion (during step (b))such that polymerisation of the monomers (and simultaneous grafting ofthe polysaccharide onto the polymer particles) proceeds.

A preferred process comprises the steps of:

-   (i) monomers are mixed with a cosurfactant to form a mixture (y),-   (ii) a polysaccharide and a surfactant are dissolved in water to    form a mixture (z),-   (iii) (y) and (z) are combined and subjected to high shear to form a    miniemulsion and-   (iv) an initiator is added such that polymerisation (and    simultaneous grafting of the polysaccharide onto the polymer    particles) proceeds.

The resulting polymer particles preferably have a particle size of lessthan 1 micron, more preferably of less than 500 nm.

High Shear as used herein is applied using any suitable apparatus suchas an ultrasound sonicat, or, microfluidizer or homogenizer. High Shearas used in step (iv) above is defined as shear of sufficiently highintensity that the emulsion of step (iii) above is reduced in particlesize to sub-micron dimensions, preferably under 500 nm. Suitably, theemulsion of step (iv) is formed using a high shear homogeniser at 10,000to 24,000 rpm for approximately 30 seconds to 5 minutes and thensonified using a probe ultrasound sonicator (at maximum power output)for 10 minutes to generate the miniemulsion. A suitable homogeniser is aManton Gaulin homogeniser or any other make of high shear homogenizersuch as an Ultra Turrax.

The Monomers

A wide range of monomers can be used in the process of the invention. By“monomer units” as used herein is meant the monomeric units of thepolymer chain, thus references to “a polymer particle comprisinghydrophobic monomer units” as used herein means that the polymerparticles is derived from hydrophobic monomers, and so forth.

Preferably, the monomer is a monomer suitable for free radical aqueousmini emulsion polymerisation. Therefore, preferably the monomer containsat least one ethylenically unsaturated group capable of undergoingaddition polymerisation.

A mixture of monomers may be used. The monomers of the mixture may beselected according to their solubilities. Preferably, the monomermixture comprises monomers of low solubility and monomers of highsolubility.

By low solubility as used herein in reference to monomers, is meant thatthe material is soluble in water (distilled or equivalent) at aconcentration in the range of from 0.1 to 30 g/litre, at 25° C.

By high solubility as used herein in reference to monomers, is meantthat the material is soluble in water (distilled or equivalent) at aconcentration of greater than 30 g/litre, at 25° C.

In a preferred embodiment of the invention, those monomers that are oflow solubility preferably make up greater than 30%, preferably 35 to 99%of the mixture, by weight of the total monomer mixture, and thosemonomers of high solubility preferably make up less than 30%, preferably1 to 25% of the mixture, by weight of the total monomer mixture.

Examples of suitable monomers having low solubility as defined aboveinclude olefins, ethylene, vinylaromatic monomers such as divinylbenzene, styrere, α-methylstyrene, o-chlorostyrene or vinyltoluenes,esters of vinyl alcohol and monocarboxylic acids, such as vinyl acetate,vinyl propionate, vinyl n-butyrate, vinyl laurate and vinyl stearate,esters of α,β-monoethylenically unsaturated mono- and dicarboxylicacids, such as acrylic, methacrylic, maleic, fumaric and itaconic acid,with alcohols, such as methyl, ethyl, n-butyl, isobutyl and 2-ethylhexylalcohol, dimethyl or di-n-butyl maleate, nitriles ofα,β-monoethylenically unsaturated carboxylic acids, such asacrylonitrile, and conjugated dienes, such as 1,3-butadiene andisoprene. Preferred monomers include vinyl acetate, methacrylate andstyrene. Most preferred monomers include methyl methacrylate,methacrylic acid and ethylene glycol dimethacrylate.

Examples of suitable monomers having high solubility as defined aboveare α,β-monoethylenically unsaturated monocarboxylic and dicarboxylicacids and their amides, such as acrylic acid, methacrylic acid, maleicacid, fumaric acid, itaconic acid, acrylamide, methacrylamide, poly(alkylene oxide) monoacrylates and monomethacrylates, vinyl-sulfonicacid and its water-soluble salts, and N-vinyl-pyrrolidone.

Monomers which internally crosslink the emulsion droplets may also beincorporated during the polymerisation. Such crosslinkers have at leasttwo non-conjugated ethylenically unsaturated double bonds. Examples arealkylene glycol diacrylates and dimethacrylates such as ethylene glycoldiacrylate, 1,2-propylene glycol diacrylate, 1,3-propylene glycoldiacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycoldiacrylates and ethylene glycol dimethacrylate, 1,2-propylene glycoldimethacrylate, 1,3-propylene glycol dimethacrylate, 1,3-butylene glycoldimethacrylate, 1,4-butylene glycol dimethacrylate, and alsodivinylbenzene, vinyl methacrylate, vinyl acrylate, allyl methacrylate,allyl acrylate, diallyl maleate, diallyl fumarate,methylenebisacrylamide, cyclopentadienyl acrylate, and triallylcyanurate. These monomers are copolymerised mostly in amounts of from0.5 to 10% by weight, based on the total amount of monomers to bepolymerised.

In a further preferred embodiment of the invention, insoluble (i.e. veryhydrophobic) latex monomers (by “insoluble” is meant that the materialis not soluble in water (distilled or equivalent) at a concentration of0.1 g/litre or above, at 25° C.) are used. Examples include but are notlimited to long chain hydrocarbon monoacrylates and methacrylates.Preferably, the carbon chain length is greater than 10 carbon atoms, asfor example in lauryl and stearyl methacrylates.

The process of the invention can be used to produce particles fromhydrophilic monomers, i.e. monomers of solubility of greater than about30 g/litre, preferably greater than 35 g/litre, for example 40 to 45g/litre in water (distilled or equivalent) at 25° C. Examples includebut are not limited to methacrylic and acrylic acid, 2-hydroxyethylacrylates and methacrylates, glycerol acrylates and methacrylates,poly(ethylene glycol) methacrylates and acrylates, n-vinyl pyrrolidone,acryloyl morpholine, n-vinyl acetamide, vinyl caprolactone. Suchmonomers may be utilised at levels of at least 10% based on particleweight, preferably from 10 to 80%, more preferably from 15 to 50% andmost preferably from 20 to 40% by weight of the particle.

The monomer is mixed with a cosurfactant. Suitable cosurfactants for usein the present invention include hexadecane, cetyl alcohol, lauroylperoxide, n-dodecyl mercaptan, dodecyl methacrylate, stearylmethacrylate, polystyrene and polymethyl methacrylate. The preferredcosurfactant comprises hexadecane.

Initiators and chain transfer agents may also be present. Those skilledin the art will recognise that a chemical initiator will generally berequired but that there are instances in which alternative forms ofinitiation will be possible, e.g. ultrasonic initiation or initiation byirradiation.

The initiator is preferably a chemical or chemicals capable of formingfree radicals in an aqueous environment. Typically, free radicals can beformed either by homolytic scission (i.e. homolysis) of a single bond orby single electron transfer to or from an ion or molecule (e.g. redoxreactions).

Suitably, in context of the invention, homolysis may be achieved by theapplication of heat (typically in the range of from 50 to 100° C.). Someexamples of suitable initiators in this class are those possessingperoxide (—O—O—) or azo (—N═N—) groups, such as benzoyl peroxide,t-butyl peroxide, hydrogen peroxide, azobisisobutyronitrile and ammoniumpersulphate. Homolysis may also be achieved by the action of radiation(usually ultraviolet), in which case it is termed photolysis. Examplesare the dissociation of 2,2′-azobis (2-cyanopropane) and the formationof free radicals from benzophenone and benzoin.

Redox reactions can also be used to generate free radicals. In this casean oxidising agent is paired with a reducing agent which then undergo aredox reaction. Some examples of appropriate pairs in the context of theinvention are ammonium persulphate/sodium metabisulphite, cumylhydroperoxide/ferrous ion and hydrogen peroxide/ascorbic acid.

Preferred initiators are be selected from the following: Homolytic:benzoyl peroxide, t-butyl peroxide, hydrogen peroxide,azobisisobutyronitrile, ammonium persulphate, 2,2′-azobis(cyanopropane), benzophenone, benzoin, Redox: ammoniumpersulphate/sodium metabisulphite mixture, cumyl hydroperoxide/ferrousion mixture and/or hydrogen peroxide/asorbic acid mixture. The preferredinitiator is ammonium persulphate. The preferred level of initiator isin the range of from 0.1 to 5.0% w/w by weight of monomer, morepreferably, the level is in the range of from 1.0 to 3.0% w/w by weightof monomer.

Chain transfer agents can optionally be used to reduce the degree ofpolymerisation and hence the final molecular weight of the polymer. Achain transfer agent contains very labile hydrogen atoms that are easilyabstracted by a propagating polymer chain. This terminates thepolymerisation of the growing polymer, but generates a new reactive siteon the chain transfer agent that can then proceed to initiate furtherpolymerisation of the remaining monomer. Chain transfer agents in thecontext of the invention typically contain thiol (mercaptan)functionality and can be represented by the general chemical formulaRS—H, such as n-dodecyl mercaptan and 2-mercaptoethanol. The preferredchain transfer agent is monothioglycerol, used at levels of, preferablyfrom 0 to 5% w/w based on the weight of the monomer and more preferablyat a level of 0.25% w/w based on the weight of the monomer.

The Benefit Agent

The polysaccharide-grafted polymer particle (i.e. without additionalbenefit agent) produced by the process of the invention, if applied tothe fabric during laundering, may provide one or more benefits to thefabric, selected from but not limited to: stiffening, starching,softening, drape modifying, lubricating, elastomeric, shape retention,crease reduction, ease of ironing, moisturising, colour preservation andanti-pilling, depending on the specific particle monomers utilised.

However, preferably, the polysaccharide-grafted polymer particlecontains an additional benefit agent when used in laundering. Whenpresent, this additional benefit agent is pre-mixed, preferablypre-dissolved in the monomers. The presence of the additional benefitagent may enhance the benefit(s) conferred by the polymer particleitself (listed above) and/or confer further benefit(s).

The benefit agent may be any agent that is capable of impartingdesirable properties to the substrate it is applied to. Preferably, thebenefit agent is a fabric benefit agent.

A fabric benefit agent is any suitable agent which affects the feel,appearance, or perception of a fabric. The fabric benefit agent may beselected from, but is not limited to, the following: fabric softeners,lubricants, ease of ironing aids, stiffening agents, moisturisingagents, shape retention aids, crease reduction agents, anti-pillingagents, colour preservatives, perfumes, drape modifiers, fluorescers,sunscreens, photofading inhibitors, fungicides and insect repellents.

Suitable fabric softeners are amino functional silicone oils such asRhodorsil Oil Extrasoft supplied by Rhodia Silicones. Other siliconesmay be selected from those disclosed GB1,549,180A, EP459,821A2 andEP459822A. These silicones can also be used as lubricants. Othersuitable lubricants include any of those known for use as dye bathlubricants in the textile industry.

The process of the invention can be used to preparepolysaccharide-grafted polymer particles which comprise preformedpolymers. These may be prepared by non free radical polymerisation.Examples include but are not limited to polysiloxanes, polyesters,polyamides, polyurethanes, polyethers, epoxy resins, alkyd resins,phenolic resins. These may make up from 10 to 99%, preferably from 20 to90%, more preferably from 25 to 80% and most preferably from 40 to 80%(w/w) of the total particle.

Alternatively, the preformed polymers may comprise block copolymers, forexample ABA triblock thermoplastic elastomers. Such block copolymers maybe present at levels of from 10 to 99%, preferably from 20 to 90%, morepreferably from 25 to 80% and most preferably from 40 to 80% based ontotal particle weight.

The process of the invention can be used to preparepolysaccharide-grafted polymer particles which comprise an inorganicsolid and/or an organic solid. Preferred inorganic and organic solidsare selected from the group consisting of titanium dioxide, zinc oxide,benzophenones, pigments and organic dyes or mixtures thereof.

The process of the invention can also be used to preparepolysaccharide-grafted polymer particles which comprise a mixture ofpreformed polymers and inorganic or organic solids.

When the particles produced by the process of the invention comprisehydrophilic or very hydrophobic monomers as given above, thenpreferably, no additional preformed polymers or inorganic/organic solidsare included.

The Polysaccharide

The polysaccharide preferably has a β-1,4-linked backbone. Preferablythe polydaccharide is a cellulose, a cellulose derivative, or anotherP-1,4-linked polysaccharide having an affinity for cellulose, such aspolymannan, polyglucan, polyglucomannan, polyxyloglucan andpolygalactomannan. More preferably, the polysaccharide is selected fromthe group consisting of polyxyloglucan and polygalactomannan. Forexample, preferred polysaccharides are locust bean gum, tamarindxyloglucan, guar gum or mixtures thereof. Most preferably, thepolysaccharide is locust bean gum.

The polysaccharide acts as a delivery aid/deposition agent for theparticle (and additional benefit agent if present).

Preferably, the polysaccharide backbone has only β-1,4 linkages.Optionally, the polysaccharide has linkages in addition to the β-1,4linkages, such as B-1,3 linkages. Thus, optionally some other linkagesare present. Polysaccharide backbones which include some material whichis not a saccharide ring are also within the ambit of the presentinvention (whether terminal or within the polysaccharide chain).

The polysaccharide may be straight or branched. Many naturally occurringpolysaccharides have at least some degree of branching, or at any rateat least some saccharide rings are in the form of pendant side groups(which are therefore not in themselves counted in determining the degreeof substitution) on a main polysaccharide backbone.

Preferably, the polysaccharide is present at levels of between 0.1% to10% w/w by weight of the monomer, preferably 2% w/w by weight ofmonomer.

Grafted Polysaccharide

During the miniemulsion polymerisation step of the process of theinvention, the polysaccharide becomes grafted to the polymer particle.By grafted as used herein, in the context of the invention, is meantattached. Attachment may be by means of a covalent bond, entanglement orstrong adsorption, preferably by a covalent bond or entanglement andmost preferably by means of a covalent bond. By entanglement as usedherein is meant that the polysaccharide is adsorbed onto the particleduring the particle formation stage and consequently, as thepolymerisation proceeds and the particle grows in size, part of theadsorbed polysaccharide becomes buried within the interior of theparticle. Hence at the end of the polymerisation, part of thepolysaccharide is entrapped and bound in the particle polymer matrix,whilst the remainder is free to extend into the aqueous phase.

By strong adsorption as used herein is meant strong adsorption of thepolysaccharide to the surface of the particle; such adsorption can, forexample, occur due to hydrogen bonding, Van Der Waals or electrostaticattraction between the polysaccharide chains and the particle.

The grafted polysaccharide is thus mainly attached to the particlesurface and is not, to any significant extent, distributed throughoutthe internal bulk of the particle. This is distinct from graftcopolymers in which a polysaccharide may be grafted along the length ofa polymer chain. A particle which is formed from a graft copolymerwould, therefore, contain polysaccharide throughout the internal bulk ofthe particle as well as on the particle surface. Thus the particle whichis produced according to the process of the invention can be thought ofas a “hairy particle”, which is different from a graft copolymer. Thisfeature of the invention provides significant cost reductionopportunities for the manufacturer as much less polysaccharide isrequired to achieve the same level of activity as systems which utilisepolysaccharide copolymers.

The Polysaccharide-Grafted Particle

When used in laundering, the polysaccharide-grafted polymer particledeposits onto the fabric, preferably cotton, at higher levels thannon-polysaccharide particles. The polysaccharide-grafted polymerparticle may be used in the treatment of fabric, preferably cotton. Suchtreatment may provide a stiffening, softening, drape modifying,lubricating, elastomeric, shape retention, crease reduction, ease ofironing, moisturising, colour preservation, anti-pilling benefit to thefabric dependent on particle monomers utilised.

When additional benefit agents are used, either additional propertiesdepending on the benefit agent used will be imparted to the fabric,and/or the benefits conferred by the particle itself will be enhanced.

Alternatively, the polysaccharide-grafted polymer particle may beincorporated into a laundry treatment composition and used in thetreatment of fabric, preferably cotton.

The polysaccharide-grafted polymer particles produced by the process ofthe present invention may also be used as stiffening finishes or drapemodifiers for the textile finishing industry, as binders for paper andcard production, as performance enhancers for wood and paper adhesivesand as self-priming agents for wood paints. Thus, applications otherthan in the fabric care field are contemplated by the present invention.

As mentioned above, the particles of the invention may be thought of as“hairy particles”. The term “hairy particles” is known in the art and isgenerally defined as particles with attached polymer chains such thatpart of the polymer is attached or buried in the particle matrix and theremainder of the polymer is free to extend into the surrounding waterphase.

Laundry Treatment Compositions

The polysaccharide-grafted particles may be incorporated into laundrycompositions.

The polysaccharide-grafted particles are typically included in saidcompositions at levels of from 0.001% to 10%, preferably from 0.005% to5%, most preferably from 0.01% to 3% by weight of the total composition.

The active ingredient in the compositions is preferably a surface activeagent or a fabric conditioning agent. More than one active ingredientmay be included. For some applications a mixture of active ingredientsmay be used.

The compositions of the invention may be in any physical form e.g. asolid such as a powder or granules, a tablet, a solid bar, a paste, gelor liquid, especially, an aqueous based liquid. In particular thecompositions may be used in laundry compositions, especially in liquid,powder or tablet laundry composition.

The compositions of the present invention are preferably laundrycompositions, especially main wash (fabric washing) compositions orrinse-added softening compositions. The main wash compositions mayinclude a fabric softening agent and the rinse-added fabric softeningcompositions may include surface-active compounds, particularlynon-ionic surface-active compounds.

The detergent compositions of the invention may contain a surface-activecompound (surfactant) which may be chosen from soap and non-soapanionic, cationic, non-ionic, amphoteric and zwitterionic surface-activecompounds and mixtures thereof. Many suitable surface-active compoundsare available and are fully described in the literature, for example, in“Surface-Active Agents and Detergents”, Volumes I and II, by Schwartz,Perry and Berch.

The preferred detergent-active compounds that can be used are soaps andsynthetic non-soap anionic, and non-ionic compounds.

The compositions of the invention may contain linear alkylbenzenesulphonate, particularly linear alkylbenzene sulphonates having an alkylchain length of from C8 to C15.

It is preferred if the level of linear alkylbenzene sulphonate is from 0wt % to 30 wt % %, more preferably from 1 wt % to 25 wt %, mostpreferably from 2 wt % to 15 wt %, by weight of the total composition.

The compositions of the invention may contain other anionic surfactantsin amounts additional to the percentages quoted above. Suitable anionicsurfactants are well-known to those skilled in the art. Examples includeprimary and secondary alkyl sulphates, particularly C8 to C15 primaryalkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylenesulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates.Sodium salts are generally preferred.

The compositions of the invention may also contain non-ionic surfactant.Nonionic surfactants that may be used include the primary and secondaryalcohol ethoxylates, especially the C8 to C20 aliphatic alcoholsethoxylated with an average of from 1 to 20 moles of ethylene oxide permole of alcohol, and more especially the C10 to C15 primary andsecondary aliphatic alcohols ethoxylated with an average of from 1 to 10moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionicsurfactants include alkylpolyglycosides, glycerol monoethers, andpolyhydroxyamides (glucamide).

It is preferred if the level of non-ionic surfactant is from 0 wt % to30 wt %, preferably from 1 wt % to 25 wt %, most preferably from 2 wt %to 15 wt %, by weight of the total composition.

Any conventional fabric conditioning agent may be used in thecompositions of the present invention. The conditioning agents may becationic or non-ionic. If the fabric conditioning compound is to beemployed in a main wash detergent composition the compound willtypically be non-ionic. For use in the rinse phase, typically they willbe cationic. They may for example be used in amounts from 0.5% to 35%,preferably from 1% to 30% more preferably from 3% to 25% by weight ofthe composition.

Suitable cationic fabric softening compounds are substantiallywater-insoluble quaternary ammonium materials comprising a single alkylor alkenyl long chain having an average chain length greater than orequal to C20 or, more preferably, compounds comprising a polar headgroup and two alkyl or alkenyl chains having an average chain lengthgreater than or equal to C14. Preferably the fabric softening compoundshave two long chain alkyl or alkenyl chains each having an average chainlength greater than or equal to C16. Most preferably at least 50% of thelong chain alkyl or alkenyl groups have a chain length of C18 or above.It is preferred if the long chain alkyl or alkenyl groups of the fabricsoftening compound are predominantly linear.

Quaternary ammonium compounds having two long-chain aliphatic groups,for example, distearyldimethyl ammonium chloride and di(hardened tallowalkyl) dimethyl ammonium chloride, are widely used in commerciallyavailable rinse conditioner compositions. Other examples of thesecationic compounds are to be found in “Surfactants Science Series”volume 34 ed. Richmond 1990, volume 37 ed. Rubingh 1991 and volume 53eds. Cross and Singer 1994, Marcel Dekker Inc. New York”.

Any of the conventional types of such compounds may be used in thecompositions of the present invention.

The fabric softening compounds are preferably compounds that provideexcellent softening, and are characterised by a chain melting Lβ to Lαtransition temperature greater than 250° C., preferably greater than350° C., most preferably greater than 450° C. This Lβ to Lα transitioncan be measured by differential scanning calorimetry as defined in“Handbook of Lipid Bilayers”, D Marsh, CRC Press, Boca Raton, Fla., 1990(pages 137 and 337).

Substantially water-insoluble fabric softening compounds are defined asfabric softening compounds having a solubility of less than 1×10⁻³ wt %in demineralised water at 20° C. Preferably the fabric softeningcompounds have a solubility of less than 1×10⁻⁴ wt %, more preferablyfrom less than 1×10⁻⁸ to 1×10⁻⁶ wt %.

Especially preferred are cationic fabric softening compounds that arewater-insoluble quaternary ammonium materials having two C12–22 alkyl oralkenyl groups connected to the molecule via at least one ester link,preferably two ester links. An especially preferred ester-linkedquaternary ammonium material can be represented by the formula:

wherein each R5 group is independently selected from C1–4 alkyl orhydroxyalkyl groups or C2–4 alkenyl groups; each R6 group isindependently selected from C8–28 alkyl or alkenyl groups; and whereinR7 is a linear or branched alkylene group of 1 to 5 carbon atoms, T is

and p is 0 or is an integer from 1 to 5.

Di(tallowoxyloxyethyl) dimethyl ammonium chloride and/or its hardenedtallow analogue is an especially preferred compound of this formula.

A second preferred type of quaternary ammonium material can berepresented by the formula:

wherein R5, p and R6 are as defined above.

A third preferred type of quaternary ammonium material are those derivedfrom triethanolamine (hereinafter referred to as ‘TEA quats’) asdescribed in for example U.S. Pat. No. 3,915,867 and represented byformula:(TOCH₂CH₂)₃N+(R9)wherein T is H or (R8-CO—) where R8 group is independently selected fromC8–28 alkyl or alkenyl groups and R9 is C1–4 alkyl or hydroxyalkylgroups or C2–4 alkenyl groups. For exampleN-methyl-N,N,N-triethanolamine ditallowester or di-hardened-tallowesterquaternary ammonium chloride or methosulphate. Examples of commerciallyavailable TEA quats include Rewoquat WE18 and Rewoquat WE20, bothpartially unsaturated (ex. WITCO), Tetranyl AOT-1, fully saturated (ex.KAO) and Stepantex VP 85, fully saturated (ex. Stepan).

It is advantageous if the quaternary ammonium material is biologicallybiodegradable.

Preferred materials of this class such as 1,2-bis(hardenedtallowoyloxy)-3-trimethylammonium propane chloride and their methods ofpreparation are, for example, described in U.S. Pat. No. 4,137,180(Lever Brothers Co). Preferably these materials comprise small amountsof the corresponding monoester as described in U.S. Pat. No. 4,137,180,for example, 1-hardened tallowoyloxy-2-hydroxy-3-trimethylammoniumpropane chloride.

Other useful cationic softening agents are alkyl pyridinium salts andsubstituted imidazoline species. Also useful are primary, secondary andtertiary amines and the condensation products of fatty acids withalkylpolyamines.

The compositions may alternatively or additionally contain water-solublecationic fabric softeners, as described in GB 2 039 556B (Unilever).

The compositions may comprise a cationic fabric softening compound andan oil, for example as disclosed in EP-A-0829531.

The compositions may alternatively or additionally contain nonionicfabric softening agents such as lanolin and derivatives thereof.

Lecithins and other phospholipids are also suitable softening compounds.

In fabric softening compositions nonionic stabilising agent may bepresent. Suitable nonionic stabilising agents may be present such aslinear C8 to C2–2 alcohols alkoxylated with 10 to 20 moles of alkyleneoxide, C10 to C20 alcohols, or mixtures thereof. Other stabilisingagents include the deflocculating polymers as described in EP 0415698A2and EP 0458599 B1.

Advantageously the nonionic stabilising agent is a linear C8 to C2–2alcohol alkoxylated with 10 to 20 moles of alkylene oxide. Preferably,the level of nonionic stabiliser is within the range from 0.1 to 10% byweight, more preferably from 0.5 to 5% by weight, most preferably from 1to 4% by weight. The mole ratio of the quaternary ammonium compoundand/or other cationic softening agent to the nonionic stabilising agentis suitably within the range from 40:1 to about 1:1, preferably withinthe range from 18:1 to about 3:1.

The composition can also contain fatty acids, for example C8 to C2–4alkyl or alkenyl monocarboxylic acids or polymers thereof. Preferablysaturated fatty acids are used, in particular, hardened tallow C16 toC18 fatty acids. Preferably the fatty acid is non-saponified, morepreferably the fatty acid is free, for example oleic acid, lauric acidor tallow fatty acid. The level of fatty acid material is preferablymore than 0.1% by weight, more preferably more than 0.2% by weight.Concentrated compositions may comprise from 0.5 to 20% by weight offatty acid, more preferably 1% to 10% by weight. The weight ratio ofquaternary ammonium material or other cationic softening agent to fattyacid material is preferably from 10:1 to 1:10.

It is also possible to include certain mono-alkyl cationic surfactantswhich can be used in main-wash compositions for fabrics. Cationicsurfactants that may be used include quaternary ammonium salts of thegeneral formula R1R2R3R4N+X— wherein the R groups are long or shorthydrocarbon chains, typically alkyl, hydroxyalkyl or ethoxylated alkylgroups, and X is a counter-ion (for example, compounds in which R1 is aC8–C22 alkyl group, preferably a C8–C10 or C12–C14 alkyl group, R2 is amethyl group, and R3 and R4, which may be the same or different, aremethyl or hydroxyethyl groups); and cationic esters (for example,choline esters).

The choice of surface-active compound (surfactant), and the amountpresent, will depend on the intended use of the detergent composition.In fabric washing compositions, different surfactant systems may bechosen, as is well known to the skilled formulator, for handwashingproducts and for products intended for use in different types of washingmachine.

The total amount of surfactant present will also depend on the intendedend use and may be as high as 60 wt %, for example, in a composition forwashing fabrics by hand. In compositions for machine washing of fabrics,an amount of from 5 to 40 wt % is generally appropriate. Typically thecompositions will comprise at least 2 wt % surfactant e.g. 2–60%,preferably 15–40% most preferably 25–35%, by weight of the composition.

Detergent compositions suitable for use in most automatic fabric washingmachines generally contain anionic non-soap surfactant, or non-ionicsurfactant, or combinations of the two in any suitable ratio, optionallytogether with soap.

The compositions of the invention, when used as main wash fabric washingcompositions, will generally also contain one or more detergencybuilders. The total amount of detergency builder in the compositionswill typically range from 5 to 80 wt %, preferably from 10 to 60 wt %,by weight of the compositions.

Inorganic builders that may be present include sodium carbonate, ifdesired in combination with a crystallisation seed for calciumcarbonate, as disclosed in GB 1 437 950 (Unilever); crystalline andamorphous aluminosilicates, for example, zeolites as disclosed in GB 1473 201 (Henkel), amorphous aluminosilicates as disclosed in GB 1 473202 (Henkel) and mixed crystalline/amorphous aluminosilicates asdisclosed in GB 1 470 250 (Procter & Gamble); and layered silicates asdisclosed in EP 164 514B (Hoechst). Inorganic phosphate builders, forexample, sodium orthophosphate, pyrophosphate and tripolyphosphate arealso suitable for use with this invention.

The compositions of the invention preferably contain an alkali metal,preferably sodium, aluminosilicate builder. Sodium aluminosilicates maygenerally be incorporated in amounts of from 10 to 70% by weight(anhydrous basis), preferably from 25 to 50 wt %.

The alkali metal aluminosilicate may be either crystalline or amorphousor mixtures thereof, having the general formula:0.8–1.5Na₂O.Al₂O₃.0.8–6SiO₂

These materials contain some bound water and are required to have acalcium ion exchange capacity of at least 50 mg CaO/g. The preferredsodium aluminosilicates contain 1.5–3.5 SiO2 units (in the formulaabove). Both the amorphous and the crystalline materials can be preparedreadily by reaction between sodium silicate and sodium aluminate, asamply described in the literature. Suitable crystalline sodiumaluminosilicate ion-exchange detergency builders are described, forexample, in GB 1 429 143 (Procter & Gamble). The preferred sodiumaluminosilicates of this type are the well-known commercially availablezeolites A and X, and mixtures thereof.

The zeolite may be the commercially available zeolite 4A now widely usedin laundry detergent powders. However, according to a preferredembodiment of the invention, the zeolite builder incorporated in thecompositions of the invention is maximum aluminium zeolite P (zeoliteMAP) as described and claimed in EP 384 070A (Unilever). Zeolite MAP isdefined as an alkali metal aluminosilicate of the zeolite P type havinga silicon to aluminium weight ratio not exceeding 1.33, preferablywithin the range of from 0.90 to 1.33, and more preferably within therange of from 0.90 to 1.20.

Especially preferred is zeolite MAP having a silicon to aluminium weightratio not exceeding 1.07, more preferably about 1.00. The calciumbinding capacity of zeolite MAP is generally at least 150 mg CaO per gof anhydrous material.

Organic builders that may be present include polycarboxylate polymerssuch as polyacrylates, acrylic/maleic copolymers, and acrylicphosphinates; monomeric polycarboxylates such as citrates, gluconates,oxydisuccinates, glycerol mono-, di and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates,hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates;and sulphonated fatty acid salts. This list is not intended to beexhaustive.

Especially preferred organic builders are citrates, suitably used inamounts of from 5 to 30 wt %, preferably from 10 to 25 wt %; and acrylicpolymers, more especially acrylic/maleic copolymers, suitably used inamounts of from 0.5 to 15 wt %, preferably from 1 to 10 wt %.

Builders, both inorganic and organic, are preferably present in alkalimetal salt, especially sodium salt, form.

Compositions according to the invention may also suitably contain ableach system. Fabric washing compositions may desirably contain peroxybleach compounds, for example, inorganic persalts or organicperoxyacids, capable of yielding hydrogen peroxide in aqueous solution.

Suitable peroxy bleach compounds include organic peroxides such as ureaperoxide, and inorganic persalts such as the alkali metal perborates,percarbonates, perphosphates, persilicates and persulphates. Preferredinorganic persalts are sodium perborate monohydrate and tetrahydrate,and sodium percarbonate.

Especially preferred is sodium percarbonate having a protective coatingagainst destabilisation by moisture. Sodium percarbonate having aprotective coating comprising sodium metaborate and sodium silicate isdisclosed in GB 2 123 044B (Kao).

The peroxy bleach compound is suitably present in an amount of from 0.1to 35 wt %, preferably from 0.5 to 25 wt %. The peroxy bleach compoundmay be used in conjunction with a bleach activator (bleach precursor) toimprove bleaching action at low wash temperatures. The bleach precursoris suitably present in an amount of from 0.1 to 8 wt %, preferably from0.5 to 5 wt %.

Preferred bleach precursors are peroxycarboxylic acid precursors, moreespecially peracetic acid precursors and pernoanoic acid precursors.Especially preferred bleach precursors suitable for use in the presentinvention are N,N,N′,N′,-tetracetyl ethylenediamine (TAED) and sodiumnonanoyloxybenzene sulphonate (SNOBS). The novel quaternary ammonium andphosphonium bleach precursors disclosed in U.S. Pat. No. 4,751,015 andU.S. Pat. No. 4,818,426 (Lever Brothers Company) and EP 402 971A(Unilever), and the cationic bleach precursors disclosed in EP 284 292Aand EP 303 520A (Kao) are also of interest.

The bleach system can be either supplemented with or replaced by aperoxyacid. Examples of such peracids can be found in U.S. Pat. No.4,686,063 and U.S. Pat. No. 5,397,501 (Unilever). A preferred example isthe imido peroxycarboxylic class of peracids described in EP A 325 288,EP A 349 940, DE 382 3172 and EP 325 289. A particularly preferredexample is phthalimido peroxy caproic acid (PAP). Such peracids aresuitably present at 0.1–12%, preferably 0.5–10%. A bleach stabiliser(transition metal sequestrant) may also be present. Suitable bleachstabilisers include ethylenediamine tetra-acetate (EDTA), thepolyphosphonates such as Dequest (Trade Mark) and non-phosphatestabilisers such as EDDS (ethylene diamine di-succinic acid). Thesebleach stabilisers are also useful for stain removal especially inproducts containing low levels of bleaching species or no bleachingspecies.

An especially preferred bleach system comprises a peroxy bleach compound(preferably sodium percarbonate optionally together with a bleachactivator), and a transition metal bleach catalyst as described andclaimed in EP 458 397A, EP 458 398A and EP 509 787A (Unilever).

The compositions according to the invention may also contain one or moreenzyme(s).

Suitable enzymes include the proteases, amylases, cellulases, oxidases,peroxidases and lipases usable for incorporation in detergentcompositions. Preferred proteolytic enzymes (proteases) are,catalytically active protein materials which degrade or alter proteintypes of stains when present as in fabric stains in a hydrolysisreaction. They may be of any suitable origin, such as vegetable, animal,bacterial or yeast origin.

Proteolytic enzymes or proteases of various qualities and origins andhaving activity in various pH ranges of from 4–12 are available and canbe used in the instant invention. Examples of suitable proteolyticenzymes are the subtilisins which are obtained from particular strainsof B. Subtilis B. licheniformis, such as the commercially availablesubtilisins Maxatase (Trade Mark), as supplied by Genencor InternationalN.V., Delft, Holland, and Alcalase (Trade Mark), as supplied byNovozymes Industri A/S, Copenhagen, Denmark.

Particularly suitable is a protease obtained from a strain of Bacillushaving maximum activity throughout the pH range of 8–12, beingcommercially available, e.g. from Novozymes Industri A/S under theregistered trade-names Esperase (Trade Mark) and Savinase (Trade-Mark).The preparation of these and analogous enzymes is described in GB 1 243785. Other commercial proteases are Kazusase (Trade Mark obtainable fromShowa-Denko of Japan), Optimase (Trade Mark from Miles Kali-Chemie,Hannover, West Germany), and Superase (Trade Mark obtainable from Pfizerof U.S.A.).

Detergency enzymes are commonly employed in granular form in amounts offrom about 0.1 to about 3.0 wt %. However, any suitable physical form ofenzyme may be used.

The compositions of the invention may contain alkali metal, preferablysodium carbonate, in order to increase detergency and ease processing.Sodium carbonate may suitably be present in amounts ranging from 1 to 60wt %, preferably from 2 to 40 wt %. However, compositions containinglittle or no sodium carbonate are also within the scope of theinvention.

Powder flow may be improved by the incorporation of a small amount of apowder structurant, for example, a fatty acid (or fatty acid soap), asugar, an acrylate or acrylate/maleate copolymer, or sodium silicate.One preferred powder structurant is fatty acid soap, suitably present inan amount of from 1 to 5 wt %.

Other materials that may be present in detergent compositions of theinvention include sodium silicate; antiredeposition agents such ascellulosic polymers; soil release polymers; inorganic salts such assodium sulphate; or lather boosters as appropriate; proteolytic andlipolytic enzymes; dyes; coloured speckles; fluorescers and decouplingpolymers. This list is not intended to be exhaustive. However, many ofthese ingredients will be better delivered as benefit agent groups inmaterials produced according to the first aspect of the invention.

The detergent composition when diluted in the wash liquor (during atypical wash cycle) will typically give a pH of the wash liquor from 7to 10.5 for a main wash detergent.

Particulate detergent compositions are suitably prepared by spray-dryinga slurry of compatible heat-insensitive ingredients, and then sprayingon or post-dosing those ingredients unsuitable for processing via theslurry. The skilled detergent formulator will have no difficulty indeciding which ingredients should be included in the slurry and whichshould not.

Particulate detergent compositions of the invention preferably have abulk density of at least 400 g/litre, more preferably at least 500g/litre. Especially preferred compositions have bulk densities of atleast 650 g/litre, more preferably at least 700 g/litre.

Such powders may be prepared either by post-tower densification ofspray-dried powder, or by wholly non-tower methods such as dry mixingand granulation; in both cases a high-speed mixer/granulator mayadvantageously be used. Processes using high-speed mixer/granulators aredisclosed, for example, in EP 340 013A, EP 367 339A, EP 390 251A and EP420 317A (Unilever).

Liquid detergent compositions can be prepared by admixing the essentialand optional ingredients thereof in any desired order to providecompositions containing components in the requisite concentrations.Liquid compositions according to the present invention can also be incompact form which means it will contain a lower level of water comparedto a conventional liquid detergent.

Product Forms

Product forms include powders, liquids, gels, tablets, any of which areoptionally incorporated in a water-soluble or water dispersible sachet.The means for manufacturing any of the product forms are well known inthe art. If the polysaccharide-grafted polymer particles are to beincorporated in a powder (optionally the powder to be tableted), andwhether or not pre-emulsified, they are optionally included in aseparate granular component, e.g. also containing a water solubleorganic or inorganic material, or in encapsulated form.

Substrate

When used in laundering, the substrate may be any substrate onto whichit is desirable to deposit polymer particles and which is subjected totreatment such as a washing or rinsing process.

In particular, the substrate may be a textile fabric. It has been foundthat particularly good results are achieved when using a natural fabricsubstrate such as cotton, or fabric blends containing cotton.

Treatment

The treatment of the substrate with the material of the invention can bemade by any suitable method such as washing, soaking or rinsing of thesubstrate.

Typically the treatment will involve a washing or rinsing method such astreatment in the main wash or rinse cycle of a washing machine andinvolves contacting the substrate with an aqueous medium comprising thematerial of the invention.

EXAMPLES

The present invention will now be explained in more detail by referenceto the following non-limiting examples:—

In the following examples where percentages are mentioned, this is to beunderstood as percentage by weight.

Example 1 Preparation of Locust Bean Gum-Grafted Polymer Particles byMiniemulsion Polymerisation

Polysaccharide-Grafted Polymer Particles P1 were Prepared as Follows:

Locust Bean Gum (LBG) (2 g) was added to demineralised water (369.5 g)with pH adjustment to 2.5 (via the addition of 1M HCl) and homogenisedusing a Silverson homogeniser at 10,000 rpm for 2 min. The resulting LBGsolution was then heated using an isomantle to 70° C. before beingthoroughly mixed at 10,000 rpm for 1 hour. Sodium Dodecyl Sulphate (SDS)(1.5 g) was then added to the LBG solution and allowed to dissolve.

Methyl Methacrylate (80 g), Methacrylic Acid (20 g), Ethylene Glycoldimethacrylate (1 g) and a cosurfactant Hexadecane (2 g) were added to a1 litre reaction vessel. The LBG solution previously prepared was thenadded to the reaction vessel and the components mixed using a high shearhomogeniser at 10,000 rpm for 5 min. The resulting emulsion was thensonicated on full power for 15 mins, to form the miniemulsion, with thereaction vessel submerged in ice to prevent the reactants in thereaction vessel from reaching boiling point.

A five-necked lid which was fitted with a stirrer paddle, thermometer,nitrogen purge and condenser was secured to the reaction vessel.

The miniemulsion was heated in an isomantle to 65° C. with stirring at300 rpm and purging with nitrogen. When at 65° C., the nitrogen purgewas removed from solution but nitrogen was still allowed to flow overthe surface of the reactants. An initiator solution was added to thereaction vessel to start the polymerisation. The initiator solutioncomprised ammonium persulphate (1.5 g) in deionised water (5 g).

Shortly after the addition of the initiator solution, an exotherm wasobserved that elevated the reactant temperature to ˜80° C.

After the exotherm had completed (˜20 min) an extra amount of SDS (2.5 gin 15 g demineralised water) was added to the reactants to provideadditional stabilisation against coagulation.

The reactants were allowed to react for a total of 2 hours from theaddition of initiator before the products were cooled to roomtemperature and filtered through 40 Denier nylon mesh. The total solidscontent was found to be ˜20% (by drying to constant weight in an oven).The solids were the particles comprising poly[(methylmethacrylate(80%)-co-(methacrylic acid(20%)] cross-linked with 1%ethylene glycol dimethacrylate and comprising 2% grafted LBG.

Comparative Example A, a control polymer containing no LBG, was alsoprepared in the same way with the omission of the LBG from the synthesis(the water level was increased by 2 g in order to maintain equal totalweight prior to emulsifying).

Example 2 Wash Deposition of P1 and Comparative Example A onto Cotton

Using a UV-visible Spectrophotometer a linear calibration plot forabsorbance at 400 nm versus concentration of LBG grafted co-polymerparticle was found to exist for polymer particle concentrations below800 ppm. A similar trend was observed Comparative Example A. Thesecalibration plots were then used to determine the amount of polymerparticles that deposits onto cotton in a simulated wash process.

The Simulated Wash Process

Preparation of Stock Solutions:

Surfactant Stock: (10 g/L 50:50 LAS:A7) was prepared by dissolvingLinear Alkyl Benzene Sulphonate (9.09 g LAS (55% Active)) and SynperonicA7 (5 g) in deionised water to a total of 1 litre.

Base Buffer Stock: (0.1 M) was prepared by dissolving Sodium Carbonate(7.5465 g) and Sodium Hydrogen Carbonate (2.4195 g) in deionised waterto a total of 1 litre.

Preparation of the Wash Liquor:

Base Buffer Stock (12.5 ml) and surfactant stock (12.5 ml) were added toa high density poly(ethylene) wash bottle of 150 ml capacity and 100 mlde-ionised water was added to produce a wash liquor buffered at pH 10.5and containing 1 g/L surfactant (50:50 LAS:A7).

Simulated Wash:

0.5 g of polymer particles, P1 or Comparative Example A, (800 ppm ofparticles based on wash liquor) was added to the wash liquor and theAbsorbance produced at 400 nm recorded through a 1 cm cuvette. The valueABS400 nm was used to determine, by interpolation of the calibrationplot, the amount of polymer particles in the wash liquor prior to thesimulated wash process.

A section of unfluoresced cotton measuring 20 cm by 20 cm was placedinto the wash bottle containing the wash liquor and polymer particlesand the bottle was sealed. The wash bottle was then placed into a shakerbath, thermostated at 40° C., for 1 hour to simulate a wash process.After 1 hour the cloth was removed from the wash bottle, wrung out, andthe ABS400 nm recorded of the wash liquor and the concentration ofpolymer particles in solution determined by interpolation of thecalibration plot. The wash process was carried out in triplicate.

The results are shown in Table 1.

TABLE 1 Wash Deposition of P1 and Comparative Example A onto cotton:Polymer Particles % Deposited (on initial dose) P1 30% ComparativeExample A −9%

The results in Table 1 show the much enhanced deposition induced by theLBG grafted particles onto cotton fabric, compared to those particleswithout LBG grafted onto them.

Example 3 Characterisation of the Swelling Behaviour of LBG-GraftedPolymer Particles Produced Via Miniemulsion Polymerisation

Photon Correlation Spectroscopy (PCS) was used to characterise theswelling behaviour of the LBG-grafted polymer particles. The influenceof change in solution pH and added electrolyte was investigated.

LBG-grafted polymer particles, P1, (not exceeding 0.08%) were dissolvedin the following: de-mineralised water, 0.1 M NaCl and surfactantsolutions at pH 6.5 and surfactant solution at pH 10.5.

Solution pH was altered by addition of either dilute HCl or NaOH.

The particle size was then determined using a Malvern 3000Hsa Zetasizerat 25° C.

The results are shown in Table 2.

TABLE 2 Particle Size of P1 under Various Conditions: Solvent pHParticle Diameter/nm Demineralised water. 6.5 158 Demineralised water.10.5 259 0.1 M NaCl 6.5 151 0.1 M NaCl 10.5 217 1 g/L LAS:A7 (50:50) 6.5153 1 g/L LAS:A7 (50:50) 10.5 259 1 g/L LAS:A7 (50:50) 6.5 147 in 0.1 MNaCl 1 g/L LAS:A7 (50:50) 10.5 218 in 0.1 M NaCl

The results presented in Table 2 show that the particles according tothe invention swell substantially when the solution pH goes from neutralto basic conditions.

Example 4 Synthesis of Aminosilicone Containing LBG-Grafted ParticlesVia Miniemulsion Polymerisation

Polysaccharide-Grafted Polymer Particles P2 were Prepared as Follows:

The procedure for preparing the silicone containing LBG-graftedparticles was similar to the preparation route detailed in Example 1,except the following changes were made:

-   1) Methyl methacrylate (MMA) (100 g) was used as the sole monomer    and 5 g of aminosilicone (Rhodorsil Oil Extrasoft from Rhodia    Silicones) was dissolved in the monomer prior to emulsification and    polymerisation.-   2) The water used to solubilise the LBG prior to emulsification was    reduced by 5 g.-   3) The LBG was 1.5% (w/w) of monomer.

Comparative Example B: Similarly, a control aminosilicone containingpolymer particle was prepared using methyl methacrylate as the solemonomer with the omission of LBG from the synthesis (and the water levelincreased by 1.5 g to maintain equal weight prior to emulsifying).

Comparative Example C: A further polymer particle was prepared with theomission of aminosilicone and LBG (and the water level increased by 6.5g to maintain equal weight prior to emulsifying).

Example 5 Deposition of P2 and Comparative Examples B and C onto Cotton

The wash deposition of the particles prepared in Example 4 were measuredusing a similar procedure to that given in Example 2. The linearcalibration plot for absorbance at 400 nm versus concentration was foundto extend up to 1,500 ppm and polymer particles P2 and ComparativeExamples B and C were dosed at 1,200 ppm by weight of wash solution.

The deposition of the particles of P2, Comparative Example B andComparative Example C is shown in Table 3.

TABLE 3 Deposition of particles Particles % Deposited (on initial dose)P2 46.2% B 24.1% C −2.2% (~0%)

The results in Table 3 show superior deposition of the particlesaccording to the invention compared with the comparative examples.

Example 6 Evaluation of Softening Benefit

The softness conferred to cotton by the polymer particles P2 andComparative Examples B and C prepared in Example 4 was evaluated byassessing the dynamic friction of cotton before and after treatment.

The polymer particles P2 and Comparative Examples B and C prepared inExample 4 were applied to woven cotton at a level of 2% (w/w on weightof fabric). The initial latexes contained 20% solids (particles) inwater. These were diluted with water to give a 2% (w/w) solids solutionwhich was applied to woven cotton using a ‘Padder’ (ex. Werner Mathis)as follows:

The Werner Mathis Padder was used to remove water from wet fabric bycompression between two rollers. Woven cotton sheeting (40×30 mm) wasimmersed in the 2% solids latex solution and wetted thoroughly. The‘Padder’ was set at a roller pressure of 65 and speed of 2.5 m perminute. Excess latex solution was then removed by passing the cottonsheet between the rollers of the ‘Padder.’ The fabric weight wasmonitored before and after padding to allow determination of thepercentage ‘pick-up’ on weight of fabric. This was found to be 100% andconsequently the dried fabric contained 2% of particles on weight offabric. After padding the samples were immediately tumble dried for 20minutes (high temperature cotton setting using a Zanussi TD 525 tumbledryer) and ironed flat (Philips Elance 14 iron at cotton setting).

After ironing, the samples were left overnight in a controlledtemperature and humidity room (20° C., 65% relative humidity) and allsubsequent mechanical testing was conducted under these conditions.

The dynamic friction for both treated fabrics were determined using anInstron Testometric (trademark) machine using a friction sled attachmentas follows:

The Instron Testometric (M350-5kn) is a computer controlled,programmable, fabric properties testing station. It can be used toperform a variety of fabric testing, including friction, via theattachment of a number of accessories. The Instron comprises a verticalframe with a moving cross-head with attached load cell. To measurefabric/fabric friction the friction sled attachment was fitted. Thisconsists of a rectangular platform (420×100 mm) with a pulley at one endthat is fixed to the bottom of the frame. A string is attached to thecrosshead and lopped around the pulley and attached to a metal sledge(62×62 mm, 200 g) that rest on the platform. Prior to assembly theplatform and sled are covered with the test fabric using double sidedadhesive tape. The fabric is applied such that the warp fibres on thesledge and aligned with those on the platform. The machine settings areas follows:

-   Mode=T (tension)-   Units=N (Newtons)-   Sample break detector (SBD)=0-   Speed=100 mm/min-   Return Speed=900 mm/min-   Load Cell=2 kgf-   Distance pulled=100 mm

The fabric covered sled is placed on the platform at the opposite end tothe pulley. The test is begun and the crosshead begins to movevertically and consequently the sled is slowly pulled along the fabriccovered platform. A measure of the force versus distance travelled isrecorded which is analysed by the computer to give a measurement of theco-efficient of dynamic friction for the fabric.

The results for the LBG grafted polymer particles with and withoutaminosilicone are shown in Table 4.

TABLE 4 Coefficient of Dynamic Friction for Aminosilicone LatexCoefficient of Dynamic Latex Sample Friction P2 0.682 B 0.743 C 0.739

It will be seen that the particles according to the invention (i.e. withincorporation of silicone and LBG into the latex) leads to reducedfabric friction compared to the particles outwith the invention. Thereduction in fabric friction gives the fabric a softer feel and ease ofironing benefit.

1. A process for the preparation of polysaccharide-grafted polymerparticles, wherein the polysaccharide has β-1,4 linkages, wherein thepolymer particles are made from monomers that contain at least oneethylenically unsaturated group, wherein the process for preparationcomprises miniemulsion polymerization of monomers wherein the processcomprises the steps of: (i) mixing said monomers with a cosurfactant toform a mixture (Y), (ii) dissolving a polysaccharide and a surfactant inwater to form a mixture (z), (iii) combining (y) and (z) with high shearto form a miniemulsion and (iv) adding an initiator such thatpolymerization and simultaneous grafting of the polysaccharide onto thepolymer particles proceeds.
 2. A process as claimed in claim 1 whereinthe miniemulsion has a particle size of less than 1 micron, preferablyof less than 500nm.
 3. A process as claimed in claim 1 wherein themonomers are suitable for free radical aqueous emulsion polymerization.4. A process as claimed in claim 1 wherein the monomers are chosen fromthe group consisting of olefins, ethylene, vinylaromatic monomers,divinyl benzene, esters of vinyl alcohol and monocarboxylic acids,esters of α,β-monoethylenically unsaturated mono- and dicarboxylic acidswith alcohols, dimethyl or di-n-butyl maleate, nitriles ofα,β-monoethylenically unsaturated carboxylic acids, conjugated dienes,α,β-monoethylenically unsaturated monocarboxylic and dicarboxylic acidsand their amides, vinyl-sulfonic acid and its water-soluble salts, andalkylene glycol diacrylates and dimethacrylates.
 5. A process as claimedin claim 4 wherein the monomer is selected from the group consisting ofstyrene, α-methylstyrene, o-chlorostyrene, vinyltoluenes, vinyl acetate,vinyl propionate, vinyl n-butyrate, vinyl laurate, vinyl stearate,esters of acrylic, methacrylic, maleic, fumaric or itaconic acid withmethyl, ethyl, n-butyl, isobutyl or 2-ethylhexyl alcohol, acrylonitrile,1,3-butadiene, isoprene, acrylic acid, methacrylic acid, maleic acid,fumaric acid, itaconic acid, acrylamide, methacrylamide, poly (alkyleneoxide) monoacrylates and monomethacrylates, N-vinyl-pyrrolidone,ethylene glycol diacrylate, 1,2-propylene glycol diacrylate,1,3-propylene glycol diacrylate, 1,3-butylene glycol diacrylate,1,4-butylene glycol diacrylates, ethylene glycol dimethacrylate,1,2-propylene glycol dimethacrylate, 1,3-propylene glycoldimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycoldimethacrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate,allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate,methylenebisacrylamide, cyclopentadienyl acrylate, and triallylcyanurate.
 6. A process as claimed in claim 1 wherein the polysaccharideis present at levels of from 0.1% to 10% w/w of the monomer.
 7. Aprocess as claimed in claim 1 wherein the cosurfactant is selected fromthe group consisting of hexadecane, cetyl alcohol, lauroyl peroxide,n-dodecyl mercaptan, dodecyl methacrylate, stearyl methacrylate,polystyrene and polymethyl methacrylate.
 8. A process as claimed inclaim 1 wherein the polysaccharide is selected from the group consistingof a polymannan, polyglucan, polyglucomannan, polyxyloglucan andpolygalactomannan and a mixture thereof.
 9. A process as claimed inclaim 8 wherein the polysaceharide is locust bean gum.
 10. A process asclaimed in claim 1 wherein the initiator is selected from the groupconsisting of benzoyl peroxide, t-butyl peroxide, hydrogen peroxide,azobisisobutyronitrile, ammonium persulphate, 2,2′-azobis(cyanopropane), benzophenone, benzoin, ammonium persuiphate/sodiummetabisulphite mixture, cumyl hydroperoxide/ferrous ion mixture andasorbic acid/hydrogen peroxide mixture.
 11. A process as claimed inclaim 1 wherein the polysaccharide-grafted particles contain anadditional fabric benefit agent.
 12. A process as claimed in claim 11wherein the fabric benefit agent is selected from the group consistingof fabric softeners, lubricants, ease of ironing aids, stiffeningagents, moisturising agents, shape retention aids, crease reductionagents, anti-pilling agents, colour preservatives, perfumes, drapemodifiers, fluorescers, sunscreens, photofading inhibitors, fungicidesand insect repellents.
 13. A method of treating fabric, comprising (I)preparing polysaccharide-grafted polymer particles, wherein thepolysaccharide has β-1,4linkages, wherein the polymer particles are madefrom monomers that contain at least one ethylenically unsaturated group,wherein preparing said polymer particles comprises miniemulsionpolymerization of monomers, which comprises the steps of: (i) mixingsaid monomers with a cosurfactant to form a mixture (y), (ii) dissolvinga polysaccharide and a surfactant in water to form a mixture (z), (iii)combining (y) and (z) with high shear to form a miniemulsion and (iv)adding an initiator such that polymerization and simultaneous graftingof the polysaccharide onto the polymer particles proceeds to formpolysaccharide-grafted polymer particles, and (II) contacting the fabricwith said polysaccharide-grafted polymer particles.
 14. A method oftreating fabric to deliver one or more benefit agents to the fabriccomprising (I) preparing polysaccharide-grafted polymer particles,wherein the polysaccharide has β-1,4linkages, wherein the polymerparticles are made from monomers that contain at least one ethylenicallyunsaturated group, wherein preparing said polymer particles comprisesminiemulsion polymerization of monomers, which comprises the steps of:(i) mixing said monomers with a cosurfactant to form a mixture (y), (ii)dissolving a polysaccharide and a surfactant in water to form a mixture(z), (iii) combining (y) and (z) with high shear to form a miniemulsionand (iv) adding an initiator such that polymerization and simultaneousgrafting of the polysaccharide onto the polymer particles proceeds toform polysaccharide-grafted polymer particles, and (II) contacting thefabric with said polysaccharide-grafted polymer particles and one ormore benefit agents.
 15. The method of claim 14, wherein the method isapplied to cotton, to provide one or more of a fabric softening,lubricant, ease of ironing, stiffening, moisturising, shape retention,crease reduction, anti-pilling, colour preserving, perfume enhancing,drape modifying, fluorescent, sunscreen, photofading inhibition,fungicidal or insect repellent effect to the fabric.